I searched through the settings and help but i still don't have a solution.. Maybe claim only works if someone actually paid for the game? Until that miracle happens i won't know for sure, y'all have to be contempt with just keeping it in your collection i'm afraid (it will stay pay-what-you-want forever anyway)

It seems that game had a price at one point and went on sale (and was not just pay-what-you-want from the beginning like this one)Anyway if anyone is still hellbent on claiming just contact me somehow (like pm me on reddit or send a mail to mutgame(at)gmail.com ) and i'll send you a key